2. Protein Structure………………………………………………………………………………………….…...1

1 & 2

Protein Structure

1- In an amino acid, the carboxyl group and amino group are separated from each other by a single ____________ atom.

a. nitrogen b. Sulphur c. hydrogen d. carbon ANS: d

2- Amino acids used in the synthesis of proteins on a ribosome are

a. D-amino acids b. Mutated amino acids c. L-amino acids d. Fluorescing amino acids ANS: c

3- Which bonds are present in two neighboring amino acids?

a. Glycosidic bonds b. Polypeptide bonds c. Amide bonds d. Hydrogen bonds ANS: b

4- Which residues are present in histone proteins?

a. Lysine & proline b. Glutamic acid & aspartic acid c. Arginine & Histidine d. Serine & Cysteine ANS: c

5- Keratin is:

a. Fibrous protein.

a. Globular protein b. Tripeptide. c. Histone. d. Conjugated protein. ANS: a

6- An essential amino acid in man is:

a. Proline. b. Tyrosine. c. Methionine. d. Serine. e. Glycine ANS: c

7- Formed of 3 alpha-polypeptide chains; and contains about 33% glycine:

a. Keratin b. Collagen c. Albumin d. Elastin ANS: b

8- Thyroxin hormone is derived from:

a. Tyramine. b. Tyrosine. c. Tryptophan. d. Taurine. e. Tryptamin ANS: b

9- Primary structure of proteins is determined by:

a. Peptide bonds b. Hydrogen bonds c. Disulfide bonds d. Electrostatic bond